1. Department of Mathematics, Faculty of Science and Humanities, Prince Sattam Bin Abdulaziz University, Alkharj, Saudi Arabia
2. Department of Mathematics, Faculty of Science, New Valley University, Elkharga, Egypt
3. College of Mathematics and Information Science, Shaanxi Normal University, Xi’an, P.R. China
4. Department of Mathematics, Faculty of Science, Al-Azhar University, Assiut 71524, Egypt